Just Ask the Expert: What role does genetics play in a pet's temperament?

Dr. Tynes welcomes behavior questions from veterinarians and veterinary technicians.Click here to submit your question, or send an e-mail to vm@advanstar.com with the subject line "Behavior questions."

I have heard in lectures that male cats contribute proportionately more genetic influence on offspring behavior than do females, probably to balance the fact that females have more socialization influence than absent males. If this is true, do you know of a scientific reference to support this, or is this theoretical?

Similarly, do you think a male dog contributes more genetic influence on behavior? I work with a canine breeding kennel that wants to improve the personality of their puppies. Would it be worthwhile for them to find a healthy dog of the correct breed with a great personality and buy its semen to artificially inseminate their bitches?

We should all be familiar with this subject since it is so critical that we play a role in educating breeders about the importance of breeding animals that are behaviorally as well as physically sound. A great deal of research over the years has clearly demonstrated that many behavioral traits have a genetic basis in both dogs and cats. The research in cats, in particular, has demonstrated that the friendliness of the father has a significant effect on the friendliness of its offspring, regardless of the amount of early handling received by the kittens.

However, no study has clarified the genetic role of the queen on offspring friendliness. In order to do this, several litters of kittens with the same father would have to be cross-fostered by mothers of differing levels of friendliness. If an unfriendly mother raised a kitten from a friendly father and friendly mother, the resulting behavior of that kitten might help us to separate the genetic effects from the environmental effects. For example, if the kitten grew up to be unfriendly, that would suggest that environmental effects may outweigh genetics, at least regarding this one trait. If, conversely, a kitten with the same friendly father but an unfriendly mother could be raised by a friendly mother, its resulting behavior, especially if significantly different from that of the other kittens, could add even more to the picture. If this kitten turned out to be unfriendly, that could suggest that the mother's genetics played a more important role than the father's genetics and the environment. Ultimately, without removing the kittens from their own mother, the environmental effects cannot be separated from the genetic effects.

Studies of temperament and personality in dogs have also suggested varying degrees of heritability of different personality traits. In particular, shyness or fearfulness seems to have a high heritability. Other studies have determined that aggression and a characteristic the researchers called boldness are heritable. While some studies have suggested the presence of stronger maternal influences on behavior, others have found minimal maternal influence on behavior, and none appear to have specifically looked at paternal genetic influences. Clearly, we still have much to learn about the genetics of behavior.

While it is understood that each parent contributes half of their offsprings' genetic material, whether or not they vary in their specific contributions to different traits remains to be elucidated. Until more is learned, it would be ideal to encourage breeders to evaluate all potential breeding animals equally and only breed animals that exhibit good temperament and good health.